Systems and equipment necessary for tracking one or more individuals, in real time and within a defined environment (such as, for example, a hospital complex, theme park, shopping mall, etc) provides several challenges. The system should be able to distinguish between different individuals within a defined group (for example, between different family members at a theme park) as well as be able to separately track each individual's movement and particular location at a moment's notice (if, for example, the members should become lost or separated). For this purpose, the system should provide convenient access anywhere within the environment—no matter how large the defined environment is.
Systems and equipment for tracking the location of moving objects in real time have been described in the art. For example, U.S. Pat. No. 5,764,283 discloses a “real time” method and apparatus for obtain spatial-temporal tracking corresponding to the movement of people from a continuous video stream containing video data. A clustering technique is used for tracking, in real time, “moving people” as they are represented by images obtained from the continuous video stream. Such a video-directed approach, however, is considered as suited only for tracking individuals in a very limited space, such as at the threshold of a store.
Another group of prior art systems use a type of “tagging” device, the device being associated with an individual upon entering the defined environment and thereafter periodically transmitting a beacon “identification signal”. U.S. Pat. Nos. 6,424,264 and 6,747,562 illustrate the use of such identification tags in the environment of an amusement park. Each tag includes a long range transmitter for “chirping” its particular identification signal at a predetermined rate (every few seconds, or so, for example) and a short-range passive component including a memory element with complete identification information for the individual. The information in this memory element may be used at a configured communication point (e.g., kiosk) to “locate” other members of the individual's group. In order to function at an optimum level, the closed environment must include a rather large number of receivers for the chirping ID signals (the number/location of receivers thus influencing the accuracy of the location information), as well as a fairly large number of kiosks at which an individual user may submit a “locate” request or a request identifying himself as “lost”. Given the number and complexity of other systems that are provided throughout such an environment, the equipment and space, maintenance, etc required for yet an additional overlaid communication system may be cost prohibitive.
Another problem remaining with the identification tag locating/tracking system is that the system is purely passive. There is no ability to communicate between individuals within a particular group. Thus, if a mother uses the system to locate her daughters within a particular store at a shopping mall, by the time the mother traverses the mall to reach that store, the daughters have moved on. The added ability to communicate/page with the other group members (e.g., “stay right there—I′m on my way over to you”) would be a significant benefit.